Thumbwheel switch with floatingly positioned actuator

ABSTRACT

The disclosure relates to a thumbwheel switch wherein a brush with contact fingers is mounted on a contact wheel, the contact wheel being rotatable within a housing. A printed circuit board with discrete conductive sections is placed over the housing and contacts the contact fingers, the fingers abutting different predetermined ones of the conductive sections for each setting of the contact wheel to provide a coded output indicative of the positions of the contact wheel.

United States Patent Lockard et al.

{22} Filed:

[541 THUMBWHEEL SWITCH WITH FLOATINGLY POSITIONED ACTUATOR [72] Inventors: Joseph Larue Lockard; William Henry Rose, both of Harrisburg, Pa.

AMP Incorporated, Harrisburg, Pa.

Feb. 26, 1971 [2]] Appl. No.: 119,279

[73] Assignee:

[52] US. Cl ..200/11 TW, 200/168 K [51] Int. Cl ..H0lh 9/02, HOlh 19/58 [58] Field of Search ..200/1 1 TW, 168 K [56] References Cited UNITED STATES PATENTS 3,555,211 1/1971 Silverman et al. ..200/11 TW X 3,089,923 5/1963 Wright ..200/1 1 TW X [451 May 23, 1972 3,290,456 12/1966 Meyer ..200/ 168 K X 3,306,993 2/1967 Lien ..200/11 TW 3,504,139 3/1970 Long ..200/1 1 TW 3,566,049 2/1971 Wright... ..200/11 TW X 3,286,047 11/1966 Heide ..200/11 TW Primary Examiner-J. R, Scott AttomeyWil1iam J. Keating, Ronald D, Grefe, Gerald K. Kita, Frederick W. Raring, Jay L. Seitchik and John P. Vandenburg [57] ABSTRACT The disclosure relates to a thumbwheel switch wherein a brush with contact fingers is mounted on a contact wheel, the contact wheel being rotatable within a housing. A printed circuit board with discrete conductive sections is placed over the housing and contacts the contact fingers, the fingers abutting difierent predetermined ones of the conductive sections for each setting of the contact wheel to provide a coded output indicative of the positions of the contact wheel.

8 Claims, 4 Drawing Figures Patented May 23, 1972 2 Sheets-Sheet 1 Patented May 23, 1972 3,665,127

2 Sheets-Sheet 2 TIIUMBWI-IEEL SWITCH WITH FLOATINGLY POSITIONED ACTUATOR This invention relates to a thumbwheel switch and, more particularly; to a thumbwheel switch capable of providing a unique coded output in response to individual rotary settings of a contact wheel.

Thumbwheel switches which are capable of providing a coded output, indicative of the setting of the thumbwheel are well known in the art. However, such thumbwheel switches have been relatively expensive and have not been easily miniaturized.

In accordance with the present invention, the above noted problems of the prior art thumbwheel switches are substantially reduced by provision of a rotary contact wheel of substantially the same vertical dimension as the printed circuit board with which it coactsv Briefly, the above is accomplished. by means of a housing having an annular hollow central region for receiving a contact wheel, the housing having a spring for retaining the contact wheel in preset position. The contact wheel also carries a brush with spring fingersfor contacting the conductive regions of a printed circuit board, the width of the printed circuit board being of substantially the same dimension as the diameter of the contact wheel. A snap member locks the elements together and also allows several switches to be locked in side by side relation.

It is therefore an object of this invention to provide a thumbwheel switch of relatively low cost.

It is a further object of this invention to provide a thumbwheel switch capable of providing a rotary to binary code conversion of relatively inexpensive design and small vertical dimension.

The above objects and still further objects of the invention will immediately become apparent to those skilled in the art after consideration of the following preferred embodiment thereof, which is provided by way of example and not by way of limitation, wherein:

FIG. 1 is a view in elevation of several thumbwheel switches in accordance with the present invention in side by side position to form a switch bank;

FIG. 2is an exploded view of a thumbwheel switch assembly in accordance with the present invention;

FIG. 3 is a view taken along the line 3-3 of FIG. 2; and

FIG. 4 is a partially cut away view of the switch of the present invention in the assembled state.

Referring to FIG. 2, there is shown an exploded view of the present invention which includes a housing 1 having a pair of apertures 3 and 5 in the front wall thereof and an annular portion 7 forming a hollow region 58 for receiving a contact wheel 9 as will be explained in more detail hereinbelow.

The housing 1 also includes a wall 11 positioned inwardly from the side wall 49, wall 49 also having an aperture 13 extending entirely therethrough. A detent spring 15 fits between the wall 11 and the housing wall 49 defining the aperture 13. The spring 15 has a portion which extends over the wall 11 and above the annular portion 7 of the housing 1.

The contact wheel 9 includes an annular portion 17 which fits into the hollow region 58 formed by the annular portion 7 of the housing 1 and contains numbers thereon. The annular portion 17 is floatingly positioned within annular portion 7 without rigid axial support. The contact wheel 9 also includes a rotatable thumb portion 19 and a brush 21 staked thereto by means of upwardly extending posts 23 integral with the wheel 9. The brush 21 has contact fingers 25.

A printed circuit board 27 includes an aperture 29 (better shown in FIG. 3) and conductive circuit paths 31 thereon for making contact with the fingers 25. The aperture 29 is alined over the aperture 13 of the housing 1 for securing the printed circuit board to the housing 1. A securing or locking member 61 fits over the printed circuit board 27 and the printed circuit board is properly positioned as mentioned above, the extensions 37 and 39 of member 61 being locked within the apertures 3 and 5 in the housing 1. The extensions 33 and 35 of the member 61 are utilized for mating with apertures contained in of the housing 1. The other apertures 41 and 43 of the printed circuit board 27 can also be mated with apertures 45 and 47 of the housing I if desired. The printed circuit board 27 slides over the wall 49 of the housing 1 and the wall 11 therewithin and between the walls 51 and 53 which are slightly raised relative to the walls 11 and 49 by a dimension equal to the height or smallest dimension of the printed circuit board 27. The contact wheel 9 is positioned within the aperture 58 formed by the annular region 7 in the housing portion 1 and is rotatable therein.

It can be seen that the thumb operated portions 19 of the wheel 9 extend outwardly beyondthe curved front wall 55 of the housing '1, the numbers on the wheel 9 appearing through the cutout region 57 in the housing 1. The fingers 25 on brush 21 which is staked to posts 23 of the contact wheel 9 abut the conductive regions 31 of the printed circuit board 27 in predetermined manner, depending upon the position thereof. The contact wheel 9 is held in a preset position by the spring 15 as best shown in FIG. 4. The apertures 3 and 5 receive the extensions 37 and 39 of the locking member 61 (not shown in FIG. 4), the housing 1 also including apertures such as 3 and 5 on the front portion of the housing as best shown in FIG. 1 by the apertures 3' and 5. In this manner, a pair of adjacent switches can be locked together by means of the extensions 33, 35, 37 and 39. Such an arrangement is shown in FIG. 1 wherein a bank of such switches is provided.

In operation, the switch as best shown in FIG. 4 is operated by rotating the thumb portions 19 of the contact wheel 9 so that the desired number is positioned in the aperture 57 of the housing 1. At this time, the fingers 25 of the brush 21 will contact preselected ones of the conductive paths 31 on the printed circuit board 27, thereby providing an output unique to the selected number at the output of the switch. In this manner, an electrical output is provided indicative of the selected number.

It can be seen that the thumb wheel switch in accordance with the present invention has a vertical height which is restricted to substantially the height of the printed circuit board. Accordingly, the switch has minimum height relative to prior art switches of this type.

Though the invention has been described in respect to a specific preferred embodiment thereof, many variations and modifications thereof will become apparent to those skilled in the art. It is therefore the intention that the appended claims be interpreted as broadly as possible in view of the prior art to include all such variations and modifications.

What is claimed is:

1. A switch which comprises a housing, a hollow cylindrically shaped region defined by said housing, a contact wheel having a cylindrically shaped portion floatingly positioned in said hollow region and rotatable therein, electrical contact means positioned on said contact wheel and a printed circuit board having concentric conductive regions selectively contacting said contact means and means locking said contact wheel and said printed circuit board within said housing, further including spring means positioned in said housing and means on said contact wheel for selectively positioning said contact wheel in said housing.

2. A switch as set forth in claim 1 wherein said means securing includes a locking member having front and rear surfaces 4. A switch as set forth in claim 2 wherein said locking member is resilient.

5. A switch as set forth in claim 3 wherein said locking member is resilient.

6. A switchwhich comprises a housing, a hollow cylindrically shaped region defined by said housing, a contact wheel having a cylindrically shaped portion floatingly positioned in said hollow region and rotatable therein, electrical contact means positioned on said contact wheel and a printed circuit board having concentric conductive regions selectively contacting said contact means and means locking said contact wheel and said printed circuit board within said housing, further including spring means positioned in said housing and means on said contact wheel for selectively positioning said contact wheel in said housing, said printed circuit board forming a side wall with said housing, said housing and said printed circuit each defining an aperture, and said means locking including means positioned through said apertures for securing said printed circuit board to said housing.

7. A switch as set forth in claim 6 wherein said means securing includes a locking member having front and rear surfaces and a pair of extensions extending from each of said front and rear surfaces, said housing defining a pair of apertures in the walls therein for mating with the extensions on one of said front and rear surfaces. I

8. A switch as set forth in claim 7 further including a second housing mating with the extensions on the other of said front and rear surfaces. 

1. A switch which comprises a housing, a hollow cylindrically shaped region defined by said housing, a contact wheel having a cylindrically shaped portion floatingly positioned in said hollow region and rotatable therein, electrical contact means positioned on said contact wheel and a printed circuit board having concentric conductive regions selectively contacting said contact means and means locking said contact wheel and said printed circuit board within said housing, further including spring means positioned in said housing and means on said contact wheel for selectively positioning said contact wheel in said housing.
 2. A switch as set forth in claim 1 wherein said means securing includes a locking member having front and rear surfaces and a pair of extensions extending from each of said front and rear surfaces, said housing defining a pair of apertures in the walls therein for mating with the extensions on one of said front and rear surfaces.
 3. A switch as set forth in claim 2 further including a second housing mating with the extensions on the other of said front and rear surfaces.
 4. A switch as set forth in claim 2 wherein said locking member is resilient.
 5. A switch as set forth in claim 3 wherein said locking member is resilient.
 6. A switch which comprises a housing, a hollow cylindrically shaped region defined by said housing, a contact wheel having a cylindrically shaped portion floatingly positioned in said hollow region and rotatable therein, electrical contact means positioned on said contact wheel and a printed circuit board having concentric conductive regions selectively contacting said contact means and means locking said contact wheel and said printed circuit board within said housing, further including spring means positioned in said housing and means on said contact wheel for selectively positioning said contact wheel in said housing, said printed circuit board forming a side wall with said housing, said housing and said printed circuit each defining an aperture, and said means locking including means positioned through said apertures for securing said printed circuit board to said housing.
 7. A switch as set forth in claim 6 wherein said means securing includes a locking member having front and rear surfaces and a pair of extensions extending from each of said front and rear surfaces, said housing defining a pair of apertures in the walls therein for mating with the extensions on one of said front and rear surfaces.
 8. A switch as set forth in claim 7 further including a second housing mating with the extensions on the other of said front and rear surfaces. 